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BONE CLEANING ASSEMBLY WITH A ROTATING CUTTER THAT IS DISPOSED IN A
ROTATING SHAVING TUBE THAT ROTATES INDEPENDENTLY OF THE ROTATING CUTTER

Abstract

A cleaning module for cleaning bone stock used in surgical procedures.
The cleaning module includes a shell. The shell defines a void space to
receive the bone stock. A cutter is rotating mounted in the void space. A
shaving tube, also able to rotate, is coaxially disposed about the
cutter. The cutter and shaving tube have complementary edges. A drive
assembly rotates the cutter and shaving tube at different speeds, at
different times or in different directions relative to the cutter. As a
result of the rotation of the cutter and shaving tube soft tissue
adhering to the bone stock is cut away from the bone stock by the
relative rotating of the cutting edges of the cutter and shaving tube.

1. An assembly for cleaning bone stock, said assembly comprising: a shell
defining a void space for receiving the bone stock to be cleaned; a
shaving tube having a window that is defined by at least one shaving
edge, said shaving tube being rotatably mounted in the shell void space;
a cutter disposed in the shell void space so as to be rotatably disposed
in said shaving tube adjacent the at least one shaving edge of said
shaving tube such that when said cutter is rotated, said cutter and
shaving tube shaving edge cooperate to cut soft tissue from the bone
stock; and a drive assembly connected to said shaving tube, and said
cutter for actuating said shaving tube and said cutter and said drive
assembly is adapted to, when actuating said shaving tube and said cutter,
cause said shaving tube and cutter to rotate at different speeds or
directions relative to each other or to cause said cutter to be rotated
continually while said shaving tube rotates periodically.

2. The assembly of claim 1, wherein said cutter includes a plurality of
cutting edges that are positioned to rotate adjacent the at least one
said shaving edge of said shaving tube so that least one shaving edge and
the plurality of cutting edges cooperate to cut the soft tissue from the
bone stock.

3. The assembly of claim 1, wherein said shaving said cutter is formed to
have plural flutes that define plural cutting edges of said cutter that
are positioned to rotate adjacent the at least one said shaving edge of
said shaving tube so that least one shaving edge and the plurality of
cutting edges cooperate to cut the soft tissue from the bone stock and
said flutes are shaped and said cutter rotates relative to said shaving
tube so that, as said cutter rotates, cut tissue is augured upwardly
between said shaving tube and said cutter.

4. The assembly of claim 3, wherein: said shaving tube has a top end; and
a structural member defining a collecting surface is located adjacent the
top end of said shaving tube for receiving the cut tissue augered between
said shaving tube and said cutter.

5. The assembly of claim 3, wherein: said shaving tube has a top end; a
structural member defining a collecting surface is located adjacent the
top end of said shaving tube for receiving the cut tissue augered between
said shaving tube and said cutter; and. a cap is attached to said shell
and disposed over the collecting surface.

6. The assembly of claim 3, wherein: said shaving tube is further formed
to have at least one debris window through which the cut tissue passes
that is separate from the window defined by the at least one shaving
edge; and a debris catch is mounted to said shaving tube to receive the
tissue that passes through the at least one shaving tube debris window.

7. The assembly of claim 1, wherein a guide is moveably disposed in said
shell to move between a disengaged position and an engaged position and
is configured to, when moving from the disengaged position to the engage
position, urge bone stock towards the window of said shaving tube and
said cutter.

8. The assembly of claim 7, wherein said guide is an arm formed to have a
containment wall that defines an enclosed space in which the bone stock
is placed, and that surrounds said shaving tube and said cutter.

9. The assembly of claim 1, wherein a tumble plate is seated in the void
space of said shell such that the bone stock sits on top of said tumble
plate and said tumble plate is able to rotate so as to reorient the bone
stock.

10. The assembly of claim 9, wherein a tumble plate is seated in the void
space of said shell such that the bone stock sits on top of said tumble
plate and said tumble plate is able to rotate so as to reorient the bone
stock and said tumble plate is connected to said cutter for simultaneous
rotation with said cutter.

11. The assembly of claim 1, wherein said drive assembly is adapted to be
transfer torque from a motor to said cutter and said shaving tube.

12. The assembly of claim 11, wherein: said drive assembly is at least
partially attached to said shell; and attached to said shell is at least
one lock feature that cooperates with a complementary lock feature
attached to a base unit that includes a motor able to actuate said drive
assembly so that said lock feature attached to said shell and the base
unit lock features releasably lock said shell to the base unit.

13. The assembly of claim 1, wherein said drive assembly is configured to
continually rotate the cutting while periodically rotating said shaving
tube.

14. The assembly of claim 1, wherein said drive assembly is configured to
rotate said shaving tube in one of the following motions relative to the
rotation of said cutter: the same direction; the reverse direction; or an
oscillatory motion.

15. The assembly of claim 1, wherein said shell is formed with at least
one lock feature configured cooperate with a complementary lock feature
attached to a base unit that includes a motor able to actuate said drive
assembly so that the said shell lock feature and the base unit lock
feature releasably lock said shell to the base unit.

16. An assembly for cleaning bone stock, said assembly comprising: a
shell defining a void space for receiving the bone stock to be cleaned; a
cutter mounted in the shell void space for rotation, said cutter having
at least one cutting edge; a shaving tube rotatably mounted in the shell
void space so as to be extend around said cutter, said shaving tube
having a window that is defined by at least one shaving edge, such that
said cutter and said shaving tube are positioned so that the at least one
cutting edge of said cutter and said shaving edge of said shaving tube
cooperate to cut soft tissue from the bone stock and, wherein said
shaving tube is able to rotate in having tube being rotatably mounted in
the shell void space; a guide moveably disposed in said shell to move
between a disengaged position and an engaged position and is configured
to, when moving from the disengaged position to the engage position, urge
bone stock towards the window of said shaving tube and said cutter; and a
drive assembly connected to said cutter, said shaving and said guide for
actuating said, cutter, said shaving tube and said guide wherein said
drive assembly is adapted to, when actuating said shaving tube and said
cutter, cause said shaving tube and cutter to rotate at different speeds
or directions relative to each other or to cause said cutter to be
rotated continually while said shaving tube rotates periodically and said
drive assembly is further configured to cyclically move said guide
between the disengaged and engaged positions of said guide.

17. The assembly of claim 16, wherein said shaving said cutter is formed
to have plural flutes that define plural cutting edges of said cutter
that are positioned to rotate adjacent the at least one said shaving edge
of said shaving tube so that least one shaving edge and the plurality of
cutting edges cooperate to cut the soft tissue from the bone stock and
said flutes are shaped and said cutter rotates relative to said shaving
tube so that, as said cutter rotates, cut tissue is augured upwardly
between said shaving tube and said cutter.

18. The assembly of claim 17, wherein: said shaving tube has a top end;
and a structural member defining a collecting surface is located adjacent
the top end of said shaving tube for receiving the cut tissue augered
between said shaving tube and said cutter.

19. The assembly of claim 16, wherein said guide is an arm formed to have
a containment wall that defines an enclosed space in which the bone stock
is placed, and that surrounds said shaving tube and said cutter.

20. The assembly of claim 16, wherein said guide is formed to have a
press block that protrudes away from a wall of said guide and said press
block has a face that, when said guide is the engaged position, presses
bone stock towards said cutter and said shaving tube.

21. The assembly of claim 16, further including a biasing device that
biases said guide towards the engaged position.

22. The assembly of claim 16, wherein said guide is mounted to said shell
and drive assembly is configured to, when the motor is actuated said
drive assembly causes said guide to move in a pivotal motion between the
disengaged position and the engaged position.

23. The assembly of claim 16, wherein said shell is formed with at least
one lock feature configured cooperate with a complementary lock features
attached to a base unit that includes a motor able to actuate said drive
assembly so that the said shell lock feature and the base unit lock
feature releasably lock said shell to the base unit.

24. The assembly of claim 16, wherein: said drive assembly is at least
partially attached to said shell; and attached to said shell is at least
one lock feature that cooperates with a complementary lock features
attached to a base unit that includes a motor able to actuate said drive
assembly so that the lock feature attached to said shell and the base
unit lock feature releasably lock said shell to the base unit.

25. The assembly of claim 16, wherein said drive assembly is adapted to
be transfer torque from a motor to said cutter and said shaving tube.

26. The assembly of claim 16, wherein said drive assembly is configured
to continually rotate the cutting while periodically rotating said
shaving tube.

26. The assembly of claim 16, wherein said drive assembly is configured
to rotate said shaving tube in one of the following motions relative to
the rotation of said cutter: the same direction; the reverse direction;
or an oscillatory motion.

27. An assembly for cleaning bone stock, said assembly including: a shell
defining a void space for receiving the bone stock to be cleaned; a
cutter mounted in the shell void space for rotation, said cutter having
at least one cutting edge; a shaving tube rotatably mounted in the shell
void space so as to be extend around said cutter, said shaving tube
having a window that is defined by at least one shaving edge, such that
said cutter and said shaving tube are positioned so that the at least one
cutting edge of said cutter and said shaving edge of said shaving tube
cooperate to cut soft tissue from the bone stock and, wherein said
shaving tube is able to rotate in having tube being rotatably mounted in
the shell void space; a tumble plate rotatably disposed in said shell
such that said cutter and said shaving tube extend upwardly from said
tumble plate so that the bone stock seats on said tumble plate; and a
drive assembly connected to said cutter, said shaving and said tumble
plate for rotating said cutter, said shaving tube and said tumble plate
wherein said drive assembly is adapted to, when rotating said shaving
tube and said cutter, cause said shaving tube and cutter to rotate at
different speeds or directions relative to each other or to cause said
cutter to be rotated continually while said shaving tube rotates
periodically and said drive assembly is further configured to cyclically
move said guide between the disengaged and engaged positions of said
guide

28. The assembly of claim 27, wherein said tumble plate is connected to
said cutter for simultaneous rotation with said cutter.

29. The assembly of claim 27, wherein: said shaving said cutter is formed
to have plural flutes that define plural cutting edges of said cutter
that are positioned to rotate adjacent the at least one said shaving edge
of said shaving tube so that least one shaving edge and the plurality of
cutting edges cooperate to cut the soft tissue from the bone stock and
said flutes are shaped and said cutter rotates relative to said shaving
tube so that, as said cutter rotates, cut tissue is augured upwardly
between said shaving tube and said cutter; said shaving tube is further
formed to have at least one debris opening through which the cut tissue
that is augered passes through and that is separate from the window
defined by the at least one shaving edge; and a debris catch with a
collection surface is located adjacent said shaving tube to receive the
tissue that passes through the debris opening of said shaving tube.

30. The assembly of claim 27, wherein: a guide is moveably disposed in
the void space of said shell to move between a disengaged position and an
engaged position and is configured to, when moving from the disengaged
position to the engage position, urge bone stock towards the window of
said shaving tube and said cutter; and said drive assembly is connected
to said guide to move said guide between the disengaged position and the
engaged position.

31. The assembly of claim 30, wherein said guide is an arm formed to have
a containment wall that defines an enclosed space in which the bone stock
is placed, and that surrounds said shaving tube and said cutter.

32. The assembly of claim 30, wherein said guide is formed to have a
press block that protrudes away from a wall of said guide and said press
block has a face that, when said guide is the engaged position, presses
bone stock towards said cutter and said shaving tube.

33. The assembly of claim 30, wherein said guide is mounted to said shell
and drive assembly is configured to, when the motor is actuated said
drive assembly causes said guide to move in a pivotal motion between the
disengaged position and the engaged position.

34. The assembly of claim 27, wherein: an arm formed to have a
containment wall is pivotally mounted in the void space of said shell,
wherein said arm is formed to have a press block that extends inwardly
from the containment wall and is mounted in the void space to move from a
disengaged position in which said press block is spaced from said cutter
and said shaving tube to an engaged positioned in which said press block
is located adjacent said cutter and said shaving tube so that, when said
arm moves from the disengaged position to the engaged position, said
press block pushes bone stock towards said cutter and said shaving tube;
and said drive assembly is connected to said arm to move said arm between
the disengaged position and the engaged position.

35. The assembly of claim 27, wherein said shell is formed with at least
one lock feature configured cooperate with a complementary lock features
attached to a base unit that includes a motor able to actuate said drive
assembly so that the said shell lock feature and the base unit lock
feature releasably lock said shell to the base unit.

36. The assembly of claim 27, wherein: said drive assembly is at least
partially attached to said shell; and attached to said shell is at least
one lock feature that cooperates with a complementary lock features
attached to a base unit that includes a motor able to actuate said drive
assembly so that the lock feature attached to said shell and the base
unit lock feature releasably lock said shell to the base unit.

37. The assembly of claim 27, wherein said drive assembly is configured
to be transfer torque from a motor to said cutter, said shaving tube and
said tumble plate.

38. The assembly of claim 37, wherein: attached to said shell is at least
one lock feature that cooperates with a complementary lock feature
attached to a base unit that includes a motor able to actuate said drive
assembly so that the lock feature attached to said shell and the base
unit lock feature releasably lock said shell to the base unit said drive
assembly includes a coupling feature for engaging a complementary
coupling feature of the motor of said base unit, so that, when said shell
is attached to the base unit, torque is transferred from the base unit
motor to said drive assembly.

39. The assembly of claim 27, wherein said drive assembly is configured
to continually rotate the cutting while periodically rotating said
shaving tube.

40. The assembly of claim 27, wherein said drive assembly is configured
to rotate said shaving tube in one of the following motions relative to
the rotation of said cutter: the same direction; the reverse direction;
or an oscillatory motion.

Description

RELATIONSHIP TO EARLIER FILED APPLICATIONS

[0001] This application is a divisional of U.S. patent application Ser.
No. 14/311,674 filed 23 Jun. 2014 now U.S. Pat. No. 9,687,361. U.S.
patent application Ser. No. 14/311,674 is a continuation of PCT Pat. App.
No. PCT/US2012/072160 filed 28 Dec. 2012. PCT App. No. PCT/US2012/072160
is a non-provisional application that claims priority from U.S. Prov.
Pat. App. No. 61/581,310 filed 29 Dec. 2011. The contents of the
above-identified applications from which this application claims priority
are incorporated herein by reference.

FIELD OF THE INVENTION

[0002] This invention relates to an assembly able to clean bone stock for
use in surgical procedures.

BACKGROUND OF THE INVENTION

[0003] In certain surgical procedures chip-sized bone is used as filler
adjacent intact bone. For example, in a spinal fusion procedure, it is
known to place a compound formed out of milled bone chips around
implanted rods. The rods hold adjacent vertebrae in alignment. This
compound serves as a lattice upon which tissues forming the vertebrae
grow so as to form a foundation of bone around the rods. This foundation
distributes the load imposed on the rods. Bone chips can also be placed
in the intervertebral disc space or into a cage positioned in the
intervertebral disc space.

[0004] Bone chips are also used as filler and/or growth formation lattice
in orthopedic surgical procedures and maxillofacial procedures. Bone
chips are used as a filler and/or growth formation lattice in these
procedures because the proteins from which the bone is formed serve as
make-up material from which the blast cells of the adjacent living bone
cells form new bone.

[0005] The ideal source of bone stock for bone chips is the patient into
whom the bone chips are to be packed. This is because the patient's own
bone is less likely than donor bone to be rejected by the patient's
immune system. Accordingly, in a procedure in which bone chips are
required, bone stock is often harvested from one of the patient's bones
that can afford to lose a small section of bone, typically between 0.25
and 3 cubic centimeters. Bone that is removed from the patient for
transplant into another part of the patient is referred to as autograft
bone.

[0006] Converting autograft bone stock into bone chips can generally be
considered a two part process. In the first part of the process, the
harvested bone is cleaned to remove the ligaments and other soft tissue
that is not suitable for forming bone chips. The cleaned bone is then
milled into bone chips. The Applicant's Assignee's U.S. Patent
Application Pub. No. US 2009/0118735 A1 and PCT Pub. No. WO 2009/061728
A1, BONE MILL INCLUDING A BASE AND A MILL HEAD SEPARATE FROM THE BASE,
THE MILL HEAD INCLUDING A REMOVABLE CATCH TRAY, the contents of which are
hereby incorporated by reference, discloses an electrically operated bone
mill capable of converting bone stock into bone chips.

[0007] In a typical bone cleaning process, prior to milling the bone,
surgical personnel manually clean the bone. Presently, surgical personnel
perform this manual process using curettes and/or rongeurs. It may take
15 minutes or more for surgical personnel to perform this task.

[0008] Moreover, to perform the cleaning process, the surgical personnel
may need to firmly grasp the bone. Exerting such force on the bone may
cause tearing of the gloves worn by the surgical personnel. Furthermore,
the sharp cutting tools being used by the surgical personnel could cut or
tear through the gloves. Such cutting or tearing through the gloves could
result in the possibility that skin of the surgical personnel may come
into direct contact with the bone. This contact can result in
contamination of the bone.

[0009] Therefore, there is a need in the art for assemblies that remove
soft tissue from bone while reducing the need for manual grasping and
cleaning of the bone.

SUMMARY OF THE INVENTION

[0010] This invention provides an assembly for cleaning bone stock. The
assembly comprises a shell defining a void space for receiving the bone
stock to be cleaned. A cutter is disposed in the void space so that, when
actuated, the cutter cleans the bone stock by removing soft tissue from
the bone stock. A guide moves between a disengaged position and an
engaged position. The guide is configured to, when out of the disengaged
position, move bone stock received in the void space toward the cutter.

[0011] This invention also provides another assembly for cleaning bone
stock. This assembly includes a shell defining a void space for receiving
the bone stock to be cleaned. A cutter is disposed in the void space so
that, when actuated, the cutter cleans the bone stock by removing soft
tissue from the bone stock. A shaving tube is coaxially disposed about
the cutter and is supported by the shell. The cutter and the shaving tube
are configured to rotate at different speeds or directions relative to
one another.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0012] Advantages of the invention will be readily appreciated as the same
becomes better understood by reference to the following detailed
description when considered in connection with the accompanying drawings
wherein:

[0013] FIG. 1 is an elevational view of a system for cleaning bone stock
including a base unit, a cleaning module, a drive module, and a console;

[0014] FIG. 2 is a perspective view of the base unit of FIG. 1;

[0015] FIG. 3 is a perspective view of the cleaning module and drive
module;

[0016] FIG. 4 is an exploded perspective view of the cleaning module;

[0017] FIG. 5 is an exploded perspective view of the drive module;

[0018] FIGS. 6 is a cross-sectional view of the cleaning module and drive
module;

[0019] FIG. 7 is a perspective view of the cleaning module with a cap and
lid removed;

[0020] FIGS. 8 and 9 are top perspective views of a cutter, guide, shaving
tube, and tumble plate;

[0021] FIG. 10 is a top view of the cutter, guide, shaving tube, and
tumble plate illustrating different positions;

[0022] FIG. 11 is a close-up of FIG. 10 illustrating interaction between
the cutter, shaving tube, and guide with a horizontal cross-section taken
through the cutter and shaving tube;

[0023] FIG. 11A is a close-up of FIG. 10 illustrating interaction between
the cutter, shaving tube, bone stock, and guide with a horizontal
cross-section taken through the cutter and shaving tube;

[0024] FIG. 12 is a top perspective view of the guide;

[0025] FIG. 13 is a bottom perspective view of the guide;

[0026] FIG. 14 is a top perspective view of the cutter;

[0027] FIG. 15 is an elevational view of the cutter;

[0028] FIG. 16 is a close-up of a flute and cutting edge of the cutter of
FIGS. 14 and 15 viewed from below the cutter;

[0029] FIGS. 14A-16A are views similar to the views of FIGS. 14-16 of an
alternative cutter;

[0030] FIGS. 14B-16B are views similar to the views of FIGS. 14-16 of a
second alternative cutter;

[0031] FIG. 17 is a top perspective view of the shaving tube;

[0032] FIG. 18 is a bottom perspective view of the shaving tube;

[0033] FIG. 19 is a perspective view of the tumble plate with integrated
gear;

[0034] FIG. 20 is a top view of the tumble plate;

[0035] FIG. 21 is an exploded perspective view of the cleaning module and
drive module showing their alignment for connection;

[0036] FIG. 22 is an exploded perspective view of the cleaning module and
drive module without their shells;

[0037] FIG. 23A is a partial perspective view showing a lower portion of a
hub of the guide and a cam follower;

[0038] FIGS. 23B-23E are schematic illustrations of movement of the cam
follower and corresponding movement of the guide with FIG. 23B showing
the guide in an extreme clockwise position, FIG. 23C showing the guide
momentarily in the extreme clockwise position, FIG. 23D showing the guide
in the extreme counterclockwise position, and FIG. 23E showing the guide
in an engaged position with bone stock trapped between the guide and
cutter;

[0039] FIG. 23F is a cross-sectional view taken through the hub of guide
and the cam follower;

[0040] FIG. 24 is a top view of a cam gear;

[0041] FIG. 25 is a bottom perspective view of the cam gear showing an
indexer pin that cooperates with the indexing gear;

[0042] FIG. 26 is a top view of the indexing gear illustrating operation
of the indexer pin sliding in an indexing groove in the indexing gear;

[0043] FIG. 27 is a bottom perspective view of a cam follower;

[0044] FIG. 28 is a top perspective view of the cam follower;

[0045] FIG. 29 is an elevational view of an alternative system for
cleaning bone stock;

[0046] FIG. 30 is a perspective view of an alternative cleaning module;

[0047] FIG. 31 is an exploded perspective view of the alternative cleaning
module;

[0048] FIG. 32 is a cross-sectional view of the alternative cleaning
module;

[0049] FIG. 33 is a cross-sectional top view of an arm and a containment
ring of the alternative cleaning module;

[0050] FIG. 34 is an upper cross-sectional perspective view of the arm and
the containment ring of the alternative cleaning module;

[0051] FIG. 35 is an enlarged, fragmentary view of FIG. 34 illustrating
engagement of the arm and a shaving tube of the alternative cleaning
module;

[0052] FIG. 36 is a partial cross-sectional view of the alternative
cleaning module;

[0053] FIG. 37 is a perspective view of an arm of the alternative cleaning
module;

[0054] FIG. 38 is a top view of the arm of the alternative cleaning
module;

[0055] FIG. 39 is a bottom view of the arm of the alternative cleaning
module;

[0056] FIG. 40 is a perspective view of a containment ring of the
alternative cleaning module;

[0057] FIG. 41 is a top view of the containment ring of the alternative
cleaning module;

[0058] FIG. 42 is a perspective view of a cutter of the alternative
cleaning module;

[0059] FIG. 43 is a side view of the cutter of the alternative cleaning
module;

[0060] FIG. 44 is an end view of the cutter of the alternative cleaning
module;

[0061] FIG. 45 is a perspective view of a shaving tube of the alternative
cleaning module;

[0062] FIG. 46 is a side view of the shaving tube of the alternative
cleaning module;

[0063] FIG. 47 is a cross-sectional view of the shaving tube taken
generally along line 47-47 in FIG. 46;

[0064] FIG. 48 is a top view of a pair of debris catches of the
alternative cleaning module;

[0065] FIG. 49 is a perspective view of one of the debris catches of FIG.
48; and

[0066] FIG. 50 is a side view of the debris catches of FIG. 48 mated
together.

DETAILED DESCRIPTION

I. Assembly

[0067] Referring to the Figures, a bone cleaning system for cleaning bone
stock is generally shown at 40 in FIG. 1.

[0068] System 40 includes a base unit 42. Internal to the base unit 42 is
a drive motor 44. A drive module 45 is configured to be removably
attachable to the base unit 42 for coupling to the motor 44. A cleaning
module 46, for cleaning bone stock, is removably attachable to the drive
module 45. In the embodiment shown, the base unit 42 and drive module 45
are reusable, while the cleaning module 46 is disposable for discarding
after the bone stock is cleaned.

[0069] The cleaning module 46 includes at least one cutter 48 for cutting
soft tissue from bone stock (see FIGS. 4 and 7). Cleaning module 46 is
configured so that, when attached to the drive module 45 positioned on
base unit 42, cutter 48 is operatively connected to the motor 44 though
the drive module 45 so as to be actuated by the motor 44.

[0070] Harvested bone stock is placed in the cleaning module 46. The motor
44 is actuated so as to result in an actuation of the cutter 48. The
action of the cutter 48 cuts the soft tissue and other debris from the
bone stock while leaving a progenitor layer around the bone in place.

[0071] A control console 50 supplies electrical energization signals to
the motor 44 to actuate the motor 44. Cable 52 is connected between the
base unit 42 and console 50. Cable 52 contains the conductors (not
illustrated) over which the energization signals are supplied from the
console 50 to the motor 44.

[0072] The base unit 42 includes a circular foot 54. A leg 56 extends
upwardly from foot 54. Leg 56 is tubular in shape and has a circular
cross section. A pedestal 58 is disposed on top of the leg 56. The
pedestal 58 tapers radially outwardly from the leg 56.

[0073] Referring to FIG. 2, pedestal 58 has a generally circular top
surface 60. The pedestal is further formed to have a lip 62 that extends
upwardly and extends about the perimeter of the top surface 60. Top
surface 60 and the radially inner surface of lip 62 define a
substantially cylindrical mounting space 64 within pedestal 58. Mounting
space 64 is open at the top of the pedestal 58. The outer circumference
of lip 62, which is the outer circumference of the pedestal 58, is
smaller than a circumference of the foot 54. The outer circumference of
lip 62 is larger than that of leg 56. Pedestal 58 is further formed so as
to have an opening 66 in the center of top surface 60.

[0074] Notch 68 extends radially inwardly from the outer circumference of
pedestal 58. Notch 68 thus forms a break in lip 62. In the illustrated
version of the invention notch 68 extends radially inwardly to center
opening 66. The pedestal 58 further includes a number of
circumferentially and equiangularly spaced apart teeth 70 (only two teeth
shown in FIG. 2). Each tooth 70 extends upwardly from the pedestal top
surface 60 adjacent lip 62.

[0075] Two retention arms 72 are pivotally mounted to the pedestal 58.
Retention arms 72 are diametrically opposed and mounted to the pedestal
58 in cutouts formed in the lip 62 (cutouts not separately numbered).

[0076] Each retention arm 72 has a finger 74 that, when the arm 72 is at
rest, extends over a portion of the perimeter of pedestal top surface 60.
When the retention arms 72 are so positioned, the arms 72 are in the
"locked" state.

[0077] Each retention arm 72 has a lever 76 located below the pedestal 58.
By moving lever 76 radially inwardly, towards the underside of the
pedestal 58, the associated retention arm 72 is pivoted relative to the
pedestal 58 so as to move the corresponding finger 74 away from its
position over the pedestal top surface 60 and out of its locked state.
When the retention arms 72 are so positioned, the arms 72 are in the
"released" state.

[0078] A biasing device such as a spring (not illustrated) is disposed
between an inner surface of the pedestal 58 and each arm 72. The spring
biases its respective retention arm 72 towards its locked state. Each
retention arm 72 may be biased into its locked state by a dedicated
spring. Alternatively, both retention arms 72 may be biased into their
locked states by a common, shared spring.

[0080] The gear train 80 has a rotatable output drive shaft 82 extending
from the top of leg 56. Drive shaft 82 is disposed in the pedestal center
opening 66 below the top surface 60. Drive shaft 82 is tubular in shape.
Drive shaft 82 is provided with two diametrically opposed slots 84 (one
shown in FIG. 2) that extend longitudinally between opposite, closed ends
along drive shaft 82. Slots 84 each extend radially through the
cylindrical wall of tubular drive shaft 82. Each slot 84 has a parallel
pair of elongate interfacing sides extending between its closed, opposite
slot ends.

[0081] In some versions of the invention, motor 44 and gear train 80 are
collectively provided so that the gear train drive shaft 82 can rotate at
speeds between 100 and 500 RPM. These speeds are the under load speeds at
which the drive shaft 82 rotates during operation of the bone cleaning
system 40 when bone stock is disposed in the cleaning module 46. Motor
output shaft 78, gear train 80, and drive shaft 82 are described in
greater detail in US Pat. Pub. No. 2012/0310243 A1, hereby incorporated
by reference herein.

[0082] A drive spindle 86 is coupled to and driven by drive shaft 82. The
drive spindle 86 includes a cylindrical stem 88. At the upper axial end
of stem 88, spindle 86 has a concentric, disc shaped head 90. Spindle
head 90 is circular, and may be affixed to stem 88. Alternatively,
spindle head 90 may be integrally formed with stem 88.

[0083] A number of features extend upwardly from the planar top surface of
the spindle head 90. One of these features is an alignment pin 92. The
alignment pin 92 is coaxial with the longitudinal axis of the spindle 86
and projects upwardly from the center of the head 90. Pin 92 is
cylindrical adjacent the planar top surface of the spindle head 90.
Alignment pin 92 may be formed on the axial end of stem 88 and project
through the center of spindle head 90. Alternatively, alignment pin 92
and spindle head 90 may both be integrally formed with stem 88.
Alternatively, alignment pin 92 and spindle head 90 may be integrally
formed and affixed to the axial end of stem 88. The terminal end of
alignment pin 92 is frustoconical and provided with a flattened tip.
These features of alignment pin 92 are not separately numbered.

[0084] Four circumferentially and equiangularly spaced apart drive teeth
94 also extend upwardly from the planar top surface of the spindle head
90. Drive teeth 94 are distributed about the perimeter of the spindle
head 90. Drive teeth 94 have arcuate, radially outer surfaces that are
flush with the radially outer circular edge of the spindle head 90. Drive
teeth 94 also have arcuate, radially inner surfaces. Extending between
the radially outer and inner surfaces of each drive tooth 94 is a pair of
circumferentially opposite, inwardly tapered side surfaces; these
surfaces of drive teeth 94 are planar and perpendicular to the planar top
surface of the spindle head 90, and are not separately numbered. Drive
teeth 94 do not extend as far as alignment pin 92 does from the planar
top surface of spindle head 90.

[0085] Spindle 86 is dimensioned and positioned so that cylindrical stem
88 is slidably received in the coaxial, longitudinal bore of the tubular
drive shaft 82. A cylindrical drive pin 96 is fitted into a cross bore
(not separately numbered) extending radially through the spindle stem 88.
The opposed ends of the drive pin 96 extend from the cylindrical surface
of stem 88, and are disposed in the diametrically opposed slots 84 formed
in tubular drive shaft 82. Near its opposite ends, drive pin 96 abuts and
slidably engages the circumferentially interfacing elongate sides of the
slots 84. There is little or no relative angular movement between the
tubular drive shaft 82 and the coaxial stem 88. Rotation of the drive
shaft 82, induced by motor 44 through the gear train 80, is imparted to
the stem 88 through the abutting engagement between drive pin 96 and the
sides of slots 84.

[0086] Stem 88 and tubular drive shaft 82 have relative coaxial movement
in a range limited by the length of slots 84. In this range, and relative
to leg 56, stem 88 thus has an uppermost axial position which is limited
by abutting engagement between drive pin 96 and the top ends of slots 84,
and a lowermost axial position which is limited by abutting engagement
between drive pin 96 and the bottom ends of slots 84. The engagement
between slots 84 and drive pin 96 retains the drive spindle 86 to the
drive shaft 82 and transfers torque therebetween. Hence, the drive
spindle 86 rotates in unison with the drive shaft 82 and is able to move
longitudinally relative to the gear train 80.

[0087] A push-button switch 98 is mounted to the base unit foot 54. The
push button of switch 98 is biased with a spring (not illustrated) into
its extended position, in which switch 98 is electrically open.
Depression of the push button against this spring-biased force
electrically closes switch 98. A socket 100, shown in FIG. 1, receives
cable 52 from control console 50 and includes terminals that are
electrically connected to the cable conductors.

[0088] Internal to foot 54 is a circuit board (not illustrated)
electrically in series between socket 100 and motor 44. Mounted to the
circuit board are electrical components that function as an electric
motor controller. The function of the motor controller is to regulate
power received at socket 100 for energizing motor 44. Switch 98 is placed
electrically in series between socket 100 and the circuit board.
Alternatively, switch 98 is placed electrically in series between the
circuit board and motor 44. Power received from console 50 through cable
52 and socket 100 is regulated by the motor controller and provided to
the windings of motor 44 when switch 98 is electrically closed. Power to
the motor 44 is discontinued when the push button is released and switch
98 electrically opens. The specific structure and configuration of these
electrical components are of any suitable type well known to those of
ordinary skill in the motor control-related arts and are not illustrated.

[0089] Drive module 45 includes a shell 200. Shell 200 is dimensioned to
fit to the base unit 42 so that the base unit motor 44, when actuated,
drives a gear train 201 (see FIG. 5) in the drive module 45 that
ultimately drives the cutter 48 and other components in the cleaning
module 46 to clean bone stock.

[0090] Shell 200 has a bottom 208 and an outer wall 204. Outer wall 204
has an outer periphery that allows the shell 200 to be slip fitted into
the mounting space 64 above pedestal top surface 60 and within lip 62.

[0091] Four circumferentially and equiangularly spaced apart notches 212
extend radially inward in, and axially upward from, a downwardly directed
face of the outer wall 204 (two notches are shown in FIG. 1). Notches 212
are dimensioned so that when the shell 200 is fitted to base unit 42,
pedestal teeth 70 are seated in the notches 212. Engagement of the teeth
70 and notches 212 prevents unwanted rotation of the shell 200 relative
to the base unit 42 during operation.

[0092] Outer wall 204 is further provided with two additional side notches
214 that are diametrically opposed from each other. Side notches 214
extend radially inwardly from an outer cylindrical surface of the outer
wall 204 at a location above a bottom of the outer wall 204. More
particularly, shell 200 is formed so that when the shell 200 is seated in
pedestal mounting space 64 and teeth 70 are seated in notches 212, side
notches 214 are positioned to receive the radially inwardly directed
fingers 74 of retention arms 72.

[0093] The fingers 74 are biased radially inwardly to seat against
cooperating surfaces of the side notches 214 to selectively lock shell
200 to base unit 42. The upper surfaces of fingers 74 may be downwardly
angled radially inwardly. This allows shell 200 to slidably engage and
move fingers 74 radially outward against the biasing force acting on
retention arms 72. Thus, shell 200 may be pushed downwardly past the
fingers 74 and received in mounting space 64 without levers 76 being
manually actuated.

[0094] Shell 200 further includes a base plate 215 and a top 216. Top 216
is fixed to the outer wall 204 by fasteners, ultrasonic welding, or
adhesive (not illustrated). Base plate 215 is integral with the outer
wall 204. Outer wall 204 extends upwardly from base plate 215 to define a
lower cavity 218 of shell 200. The gear train 201 is secured to the shell
200 within the lower cavity 218.

[0095] A drive gear 226, shown in FIGS. 5 and 6, is supported to rotate
within the shell 200. In particular, a lower portion of the drive gear
226 is cylindrical and smooth and is rotatably supported by a bearing
member B in the base plate 215 of shell 200. An upper portion of the
drive gear 226 is a spur gear that is cylindrical in shape. When shell
200 is received in mounting space 64 of pedestal 58, drive gear 226
engages the spindle head 90. Driving torque is transferred from the
spindle head 90 to the drive gear 226.

[0096] Drive gear 226 has a downwardly directed face with recesses having
corresponding shapes and locations that cooperate with those of the
alignment pin 92 and the drive teeth 94 protruding upwardly from the top
surface of the spindle head 90. More particularly, drive gear 226
includes a centrally located alignment pin recess 246 and four
circumferentially and equiangularly spaced apart drive tooth-receiving
recesses 248. Recesses 246 and 248 receive alignment pin 92 and drive
teeth 94, respectively. The walls of each drive tooth recess 248 are
parallel to the respectively interfacing surfaces of the drive tooth 94
slidably received therein. Spindle head 90 and drive gear 226 thus define
a dog clutch for transferring torque from the spindle head 90 to the
drive gear 226 when shell 200 is received in mounting space 64 of
pedestal 58, and teeth 94 and recesses 248 are mated.

[0097] The cleaning module 46 also has a cleaning module shell 250.
Cleaning module shell 250 includes a cleaning module base 245. Cleaning
module base 245 has a recess (not numbered) shaped to seat on a boss (not
numbered) located on the top 216 of the shell 200 of drive module 45. An
outer peripheral wall 247 is integral with the cleaning module base 245
and extends upwardly from the cleaning module base 245. A top 249 is
fixed about its periphery to the outer peripheral wall 247 by fasteners,
ultrasonic welding, or adhesive (not illustrated).

[0098] As shown in FIG. 7, cleaning module shell 250 defines a void space
252 for receiving harvested and uncleaned bone stock. During use, cutter
48 cleans the bone stock in the void space 252 by cutting soft tissue and
other debris from the bone stock.

[0099] Cutter 48 is located within void space 252. The cutter 48 is
supported to rotate about central axis A. The cutter 48 includes a
shaving rotor 260 with helical flutes 262 having cutting edges 264 (not
shown for simplicity in FIG. 6, but see FIGS. 14-16). During operation of
system 40, cutter 48 rotates about central axis A and the cutting edges
264 clean bone stock in the void space 252 by cutting soft tissue from
the bone stock. Cutter 48 rotates in a counterclockwise direction about
central axis A (as viewed from above).

[0100] A shaving tube 270 extends coaxially about the cutter 48, as shown
in FIGS. 6 and 7. Shaving tube 270 defines a cutter window 272 through
which tissue attached to the bone stock is received for engagement by the
cutter 48. The cutter window 272 is bounded by two shaver edges 274. The
shaver edges 274 are sharp so as to cut soft tissue caught between the
shaving rotor 260 of cutter 48 and the shaving tube 270 when the shaving
rotor 260 rotates relative to the shaving tube 270. The shaver edges 274
also act as impingement structures against which soft tissue abuts and is
temporarily held to facilitate cutting by shaving rotor 260 of cutter 48.

[0101] Shaving tube 270 is configured to make one complete rotation
(approximately 360 degrees) about central axis once every 1 to 10 seconds
in a counterclockwise direction, or in some case, once every 1 to 5
seconds. Complete rotation of the shaving tube 270 alternates with
periods of time in which the shaving tube 270 is stationary and not
rotating. When rotating, shaving tube 270 rotates at about 30 to 120 RPM.

[0102] Owing to the helical geometry of flutes 262, and the relatively
slow rotation of shaving tube 270 compared to cutter 48, as the cutter 48
rotates, cut soft tissue is augered axially upwardly along cutter 48
between the cutter 48 and the shaving tube 270 to be expelled out of a
top end of the shaving tube 270 (see FIG. 6). In essence, the cutter 48
acts as a screw conveyor. The space between the cutter 48 and the shaving
tube 270 is a debris passage through which the cut soft tissue is augered
and ultimately expelled.

[0103] A lid 500 (removed in FIG. 7, but shown in FIGS. 4 and 6) is
rotatably disposed about the shaving tube 270 near the top end. The lid
500 defines a collecting surface 502 onto which the tissue that exits
from the top end of the shaving tube 270 can fall. The collecting surface
502 is spaced below the top end of the shaving tube 270 to act as a
debris catch.

[0104] The lid 500 has a slide handle 504. Handle 504 extends upwardly
from the lid 500 to be grasped by the user. The user can slide the lid
500 to uncover an opening 506 in the cleaning module shell 250 through
which the bone stock can be received to place the bone stock in the void
space 252.

[0105] A cap 508 is attached to the cleaning module shell 250 to cover and
enclose the collecting surface 502. The cap 508 defines a collecting
space into which the cut soft tissue is stored for later retrieval or
disposal.

[0106] Referring to FIGS. 8-10, which show the cleaning module 46 with
shell 250, lid 500, and cap 508 removed, a circular tumble plate 290 is
operatively coupled to the cutter 48 to rotate with the cutter 48 at the
same speed. The bone stock sits on top of the tumble plate 290 during
cleaning so that, when actuated, the tumble plate 290 carries the bone
stock to reorient the bone stock relative to the cutter 48 for more
efficient cutting of the soft tissue from the bone stock. During
operation of system 40, tumble plate 290 is driven to rotate about
central axis A.

[0107] An upper surface 292 of the tumble plate 290 carries the bone
stock. In the embodiment shown, the upper surface 292 is flat and smooth.
In some embodiments, the upper surface 292 is textured or has gripping
features (not illustrated) to grip the bone stock and facilitate moving
the bone stock.

[0108] A tubular shaft 294 is fixed to the tumble plate 290, as shown in
FIG. 6. Tubular shaft 294 extends downwardly from the tumble plate 290.
The tubular shaft 294 is coaxially disposed about the shaving tube 270.
Bearing members B are located between the tubular shaft 294 and the
shaving tube 270 to facilitate smooth relative rotation between the
tubular shaft 294 and the tumble plate 290. Likewise, a bearing member B
is located between tubular shaft 294 and cleaning module base 245. As
will be described further below, the tumble plate 290 is constantly
rotating, while the shaving tube 270 periodically rotates. Bearing
members B are shown schematically and may include bearings, bushings, or
the like.

[0109] Tumble plate 290 is disposed in a recess 243 in a top surface (not
numbered) of the cleaning module base 245 (see FIG. 6). A lower surface
(not numbered) of the tumble plate 290 rides on a raised ring-shaped
section 297 of cleaning module base 245. The ring-shaped section 297 (see
FIG. 4) is disposed in the recess 243. Upper surface 292 of tumble plate
290 is coplanar with the top surface of the cleaning module base 245. In
some embodiments, the upper surface 292 of tumble plate 290 is slightly
recesses below top surface of the cleaning module base 245. Ring-shaped
section 297 is formed of low friction material to facilitate rotation of
the tumble plate 290 thereon. Alternatively, the tumble plate 290 rides
on bearing members (not illustrated) in the recess 243.

[0110] An arm 300 extends over the planar upper surface 292 of tumble
plate 290. The arm 300 may be spaced above the upper surface 292 of
tumble plate 290 to provide a small gap therebetween. The gap can be
sized to prevent bone stock from passing therethrough. In other
embodiments, the arm 300 rides on the upper surface 292 of tumble plate
290. The arm 300 acts as a guide to direct and press the bone stock into
the cutter 48 through the cutter window 272 of the shaving tube 270. In
the embodiment shown, the arm 300 has a jalapeno-shaped containment wall
301 that defines a bone stock space 302 into which the bone stock is
initially deposited for cleaning. The bone stock space 302 moves with the
arm 300 as the arm 300 oscillates between engaged and disengaged
positions. The containment wall 301 is shaped to direct the bone stock
into position between the arm 300 and the cutter 48 when the arm 300
moves to an engaged position.

[0111] FIGS. 10 and 11 shows arm 300 moving to an extreme clockwise
position without any bone stock present in the bone stock space 302. FIG.
11A shows arm 300 in an engaged position. In the engaged position of FIG.
11A, the arm 300 is located so that bone stock is pressed into the
shaving rotor 260 of cutter 48 by a press block 304 of the arm 300
through the cutter window 272. Front face 306 of press block 304 acts as
a bearing surface that presses bone stock into cutter window 272 and
against the cutting edges 264.

[0112] It should be appreciated that the arm 300 moves between a plurality
of engaged positions and a plurality of disengaged positions. In essence,
when the front face 306 of arm 300 is pushing bone stock into the cutter
48, the arm 300 is in an engaged position, even though the rotational
position of the arm 300 may vary as more or less bone stock is located
between the front face 306 and the cutter 48. When the arm 300 is located
so that there is space between the front face 306 and cutter 48, such
that the space is not being caused by bone stock trapped therebetween,
then the arm 300 is in a disengaged position, i.e., no bone stock is
engaged and being pressed into the cutter 48.

[0113] In a disengaged position, the arm 300 is located so that the bone
stock is released from being pressed into the cutter 48 by the press
block 304 so that the bone stock is provided an opportunity to be
reoriented by the tumble plate 290. The bone stock is reoriented through
continued rotation of the tumble plate 290, which, along with cutter 48,
continues to rotate when the arm 300 is in engaged or disengaged
positions, or moving therebetween. The bone stock is further reoriented
by rotating the shaving tube 270 through one or more complete rotations
about central axis A.

[0114] Front face 306 of press block 304 is configured to follow an
arcuate path (not illustrated) to the cutter 48 when moving from a
disengaged position to an engaged position. The arm 300 is shaped so that
in an engaged position front face 306 faces the cutter 48 and containment
wall 301 corrals the bone stock into position between the front face 306
and cutter 48 so that the bone stock is trapped and pressed into the
cutter 48.

[0115] Arm 300 is periodically reciprocated between engaged and disengaged
positions to reorient the bone stock trapped between the arm 300 and the
shaving tube 270. The arm 300 pivots between engaged and disengaged
positions about 5 to 20 times per minute. The speed at which the arm 300
pivots between engaged and disengaged positions is from 5 to 20 RPM.
Movement of the arm 300 may be timed to the speed/motion of the shaving
tube 270 so that the arm 300 is in an engaged position when the shaving
tube 270 is actuated or when the shaving tube 270 is stationary.
Likewise, the arm 300 is controlled so as not to pivot during some
rotations of the shaving tube 270 when the arm 300 is in a disengaged
position.

[0116] A biasing device such as a spring 278 (see FIG. 23A) biases the arm
300 toward an engaged position. When bone stock is present and becomes
located between the front face 306 and the shaving rotor 260, then the
spring 278 acts to press the arm 300 into the bone stock to push the bone
stock against the cutter 48. Accordingly, the pressure exerted on the
bone stock against the cutter 48 can be predetermined based on the size
and properties of the spring 278.

[0117] If the bone stock should become piled or accumulate in such a way
as to overcome the bias of spring 278 the bone stock would urge the arm
300 away from the cutter 48 against the bias of spring 278. The spring
278 may be an extension spring that acts to rotate arm 300 about axis A5
toward an engaged position. The force acting on the arm 300 via the
spring 278 is transferred through the arm 300 to the bone stock. Should
the opposing force from the bone stock to the arm 300 increase beyond the
force of the arm 300 resulting from the spring 278, then the spring 278
is extended. As a result, the force acting on the bone stock is limited.

[0118] The spring 278 is associated with the arm 300 to act as a force
limiting feature so that the force with which the arm 300 presses bone
stock into the cutter 48 can be limited. The spring 278 limits damage to
the osteoblastic progenitor layer of the bone stock by keeping the force
applied to the bone stock in a range in which the osteoblastic progenitor
layer remains substantially intact after the bone stock is cleaned. The
specific force is dependent on geometry of cutter 48 and varies as the
cutter geometry varies. For instance, with cutter geometry that more
aggressively cuts material from the bone stock the force that could
result in damage to the osteoblastic progenitor layer is less than with a
cutter geometry that less aggressively cuts material from the bone stock.
Thus, the force is tuned to the cutter geometry and is determined by
identifying the force at which the osteoblastic progenitor layer remains
substantially intact, but which still substantially cleans the bone
stock.

[0119] When front face 306 engages or is at least in close proximity to
shaving tube 270, but after some amount of bone cleaning takes place,
shaving tube 270 may be rotated about central axis A to dislodge bone
stock trapped therein. Arcuate side faces 307, 309 of press block 304
provide bearing surfaces against which trapped bone stock can bear as it
is loosened or dislodged from cutter 48 and/or shaving tube 270 when the
shaving tube 270 rotates.

[0120] Referring specifically to FIG. 11, the arcuate side faces 307, 309
of press block 304 abut corresponding side faces 275, 277 of the shaving
tube 270 when the arm 300 is in an extreme clockwise position and no bone
stock is present in the bone stock space 302 between the front face 306
and shaving rotor 260. The faces 307, 309, 275, 277 are shaped for
abutting contact to prevent the front face 306 from intruding on the
cutter 48 and to maintain a gap or spacing between the front face 306 and
the cutter 48.

[0122] Arm 300 includes a hub 318 pivotally mounted to cleaning module
shell 250 about a hub pivot pin H (see FIG. 4) that is mounted to
cleaning module top 249. Hub 318 is supported for pivotal movement about
axis A5 to move arm 300 between disengaged and engaged positions. When
the cleaning module 46 is positioned on top of the drive module 45, an
interface tab 320 is positioned to be engaged by the gear train 201 so as
to move the arm 300 between engaged and disengaged positions as described
further below. The hub 318 has a semi-cylindrical or arcuate outer
surface 324 defined between the top and bottom surfaces 312, 316 of arm
300. The arm 300 further includes wing walls 326, 328 connected to hub
318 and extending divergently from hub 318 to containment wall 301 to
interconnect the hub 318 and the containment wall 301.

[0123] As shown in FIGS. 14-16, cutter 48 has a cylindrical intermediate
shaft 251 extending downwardly from the shaving rotor 260. A bearing
member B (see FIGS. 4 and 6) is located about intermediate shaft 251 to
center intermediate shaft 251 and support rotation of the cutter 48 with
shaving tube 270.

[0124] An axially lower stub shaft 254 with a non-circular cross section
extends downwardly from the intermediate shaft 251. The lower stub shaft
254 is shaped to fit within a correspondingly shaped axial bore 255 in an
axially upper section of drive gear 226. Owing to the non-circular
geometry of the cross sections of lower stub shaft 254 and its receiving
bore in drive gear 226, the cutter 48 and drive gear 226 are angularly
fixed about central axis A for rotation together when engaged. When
operating, the cutter 48 and drive gear 226 constantly rotate from 100 to
500 RPM.

[0126] The shaving rotor 260 of the cutter 48 is located axially above the
intermediate shaft 251. The shaving rotor 260 is generally cylindrical
and has an outer diameter that is larger than the diameters of the
intermediate shaft 251 and lower stub shaft 254. The shaving rotor 260,
intermediate shaft 251, and lower stub shaft 254 are integrally formed of
metal, such as stainless steel.

[0127] A plurality of flutes 262 and corresponding cutting edges 264 are
defined on shaving rotor 260. Upper 362 and lower 364 axial ends of
shaving rotor 260 are flat and lie in planes perpendicular to central
axis A. Flutes 262 and cutting edges 264 extend between the ends 362,
364. The flutes 262 and cutting edges 264 are arranged such that they
helically wrap about shaving rotor 260 between ends 362, 364 and have a
helix angle of from 20 to 70 degrees, or in some embodiments, from 30 to
60 degrees. In the embodiment shown, the cutter 48 has a helix angle of
60 degrees. An outside diameter of the shaving rotor 260 is 5/8 inches.
The cutting edges 264 each have a rake angle of between -10 and 10
degrees. In the embodiment shown, the cutting edges 264 have a rake angle
of 0 degrees. Ten flutes 262 are present in the cutter 48 shown in FIGS.
14-16.

[0128] Alternative embodiments of the cutter 48 are shown in FIGS. 14A-16A
and 14B-16B. In FIGS. 14A-16A, the cutter 48A has a helix angle of 30
degrees. An outside diameter of the shaving rotor 260A is 5/8 inches. The
cutting edges 264A have a rake angle of 0 degrees. Ten flutes 262A are
present in the cutter 48A shown in FIGS. 14A-16A. In FIGS. 14B-16B, the
cutter 48B has a helix angle of 45 degrees. An outside diameter of the
shaving rotor 260B is 5/8 inches. The cutting edges 264B have a rake
angle of 0 degrees. Ten flutes 262B are present in the cutter 48B shown
in FIGS. 14B-16B.

[0129] Referring to FIGS. 17 and 18, shaving tube 270 is generally
cylindrical and tubular for fitting over cutter 48. As shown in FIG. 17,
the cutter window 272 creates the sharp shaver edges 274 capable of
cutting soft tissue. A shaver edge 274 is located on both sides of the
cutter window 272. Thus, the shaver edges 274 further define the sides of
the cutter window 272. Surfaces 280, 282 at the top and bottom of the
cutter window 272 are generally flat and parallel. A smooth shaft section
286 of the shaving tube 270 is located below the cutter window 272. The
smooth shaft section 286 extends downwardly to a bottom end 276.

[0130] Shaver edges 274 are located so that soft tissue trapped between
shaving rotor 260 and an inner cylindrical surface 284 of shaving tube
270 is cut by the shaver edges 274 either by action of the cutter 48
rotating relative to the shaving tube 270 when the shaving tube 270 is
stationary or when the shaving tube 270 is rotating.

[0131] Tumble plate 290 is shown in FIGS. 19 and 20. The tumble plate 290
is generally circular and flat. Tubular shaft 294 is fixed to a bottom
surface (not numbered) of tumble plate 290. The tubular shaft 294 extends
downwardly from the tumble plate 290 and terminates in a gear section
296. A cylindrical passage 298 passes through the tumble plate 290,
tubular shaft 294, and gear section 296. As shown in FIG. 6, the
cylindrical passage 298 is sized to accommodate the shaving tube 270,
cutter 48, and bearing member B. In the embodiment shown, the bearing
member B is a bushing press fit into the shaving tube 270 to rotate
therewith. Gear section 296 is operatively coupled to the drive gear 226
when the cleaning module 46 is fitted onto the drive module 45 and
connected thereto.

[0132] Referring to FIGS. 21 and 22, when the cleaning module 46 is
connected to the drive module 45, the gear train 201 of drive module 45
is capable of transferring torque received from base unit motor 44 to the
cutter 48, shaving tube 270, tumble plate 290, and arm 300 of the
cleaning module 46. In the embodiment shown, the cleaning module 46 is
provided as a disposable unit designed to be utilized for one bone
cleaning session and then discarded, while the drive module 45 is
provided as a reusable unit designed to be sterilized and reused.

[0133] Referring to FIGS. 22-26, gear train 201 is located in the lower
cavity 218 of shell 200. The gear train 201 includes the drive gear 226.
When shell 200 is received in mounting space 64 of pedestal 58, drive
gear 226 engages the spindle head 90. Driving torque is transferred from
the spindle head 90 to the drive gear 226 upon actuation of the base unit
motor 44.

[0134] When the cleaning module 46 is connected to the drive module 45,
several connections are made. In one such connection, the lower stub
shaft 254 of cutter 48 is inserted into the correspondingly shaped axial
bore 255 of drive gear 226. In another connection, the gear section 296
of tubular shaft 294, which is fixed to the tumble plate 290, engages a
coupler gear 401 (see FIG. 6). The coupler gear 401 includes a lower spur
gear 402 directly driven by drive gear 226 that also engages and drives
the gear section 296. These connections establish an operative coupling
between the base unit motor 44 and cutter 48/tumble plate 290 such that
when the base unit motor 44 is actuated, drive gear 226 rotates cutter 48
and tumble plate 290 in unison about central axis A.

[0135] An upper spur gear 404 of coupler gear 401 is centrally fixed to
the lower spur gear 402 to rotate therewith about the same central axis
A2, which is fixed relative to the shell 200. Thus, when the lower spur
gear 402 is driven by the drive gear 226, the upper spur gear 404, albeit
of smaller diameter, is likewise driven.

[0136] A speed reducing gear 406 engages the upper spur gear 404 to be
driven thereby. The speed reducing gear 406 has a lower spur gear 408 and
an upper spur gear 410 of smaller diameter. The upper spur gear 410 of
speed reducing gear 406 is centrally fixed to the lower spur gear 408 of
speed reducing gear 406 to rotate therewith about the same central axis
A3, which is fixed relative to the shell 200.

[0137] A cam gear 412 engages the speed reducing gear 406 so that rotation
of the speed reducing gear 406 results in rotation of the cam gear 412.
The cam gear 412 has a cam spur gear 414 that engages the upper spur gear
410 of speed reducing gear 406 to be driven by the upper spur gear 410.
The speed reducing gear 406 reduces the rotational speed input from
coupler gear 401.

[0138] Cam gear 412 includes a cam plate 416 having a non-circular,
cam-shaped, perimeter. The perimeter has a cam outer surface 418
perpendicular to the cam spur gear 414. The cam plate 416, when viewed
from above, has a semi-circular section 420 joined by a cam section 422
(see FIG. 24). The cam section 422 protrudes radially outwardly from a
cam gear axis A4 further than the semi-circular section 420 (see FIG.
24). The cam gear axis A4 is fixed relative to the shell 200.

[0140] A cam follower 426 couples the arm 300 to the gear train 201. Cam
follower 426 has a generally cylindrical body (not numbered) with upper
and lower surfaces (not numbered). A post 428 is integrally formed with
the body and extends downwardly from the lower surface. Post 428 is
configured to generally follow along the cam outer surface 418 (although
not shown, the post 428 may include an outer bearing that rolls along the
cam outer surface 418).

[0141] A second post 429 is integrally formed with the body and extends
downwardly from the lower surface at a location spaced from the post 428.
Both posts 428, 429 are spaced radially outwardly from axis A5 (also
referred to as cam follower axis A5). One end of spring 278 is attached
to the second post 429. The other end of spring 278 is mounted to an
inner surface of outer wall 204 of shell 200 so that the spring 278 (in
this case an extension spring) is constantly biasing the cam follower 426
clockwise (viewed from above).

[0142] The cam follower 426 also has a cam interface tab 430 configured to
engage hub interface tab 320, as shown in FIG. 23A (shown without hub
pivot pin H). The cam interface tab 430 is part of the drive module 45,
while the hub interface tab 320 is part of the cleaning module 46. The
cam interface tab 430 has a first side surface S1 and a second side
surface S2. The first side surface S1 is configured to abut a third side
surface S3 of hub interface tab 320. When the first and third side
surfaces S1, S3 abut, the first and third side surfaces S1, S3 are
parallel to one another.

[0144] FIGS. 23B through 23E show movement of the cam plate 416 and
corresponding movement of the cam follower 426. FIG. 23B shows the cam
interface tab 430 engaging the hub interface tab 320 and together the arm
300 and cam follower 426 are biased into an extreme clockwise position
under the tension of spring 278. Post 428 is contacting the semi-circular
section 420 of the cam plate 416. This positional configuration occurs
when no bone stock is trapped between the front face 306 and cutter 48,
i.e., no bone stock is being cleaned.

[0145] In FIG. 23C, as the cam plate 416 rotates, the post 428 moves to
the cam section 422 of cam plate 416 from the semi-circular section 420,
thereby rotating the cam follower 426 counterclockwise (viewed from
above). Since the cam section 422 extends radially further away from the
cam gear axis A4 than the semi-circular section 420, the cam follower 426
is rotated counterclockwise about the cam follower axis A5. The cam
follower axis A5 is fixed relative to the shell 200.

[0146] When this movement of the cam follower 426 occurs, the tang 439a of
torsion spring 435 is wound toward the tang 439b. The arm 300 is thus
urged to follow the movement of the cam follower 426 via the tang 439b,
but FIG. 23C shows a delayed reaction of the arm 300, which results in a
gap forming between the first and third side surfaces S1, S3. This
delayed reaction can either be from slow reaction of the torsion spring
435 or perhaps bone stock is trapped between the arm 300 and shaving tube
270 preventing counterclockwise rotation of the arm 300.

[0147] FIG. 23D shows the arm 300 rotationally catching up with the cam
follower 426 under the torque created by torsion spring 435 resulting in
the third side surface S3 abutting the first side surface S1. The arm 300
is thus moved to disengaged positions via the torsion spring 435. The
torsion spring 435 acts to bias arm 300 counterclockwise such that
containment wall 301 engages the shaving tube 270. Accordingly, the
containment wall 301 can act as a bearing surface to loosen material when
the shaving tube 270 rotates. In FIG. 23D, the post 428 continues to
follow along the cam section 422 of the cam plate 416. In FIGS. 23C and
23D, the spring 278 acts to bias the post 428 of the cam follower 426
against the outer surface 418 of the cam plate 416 when the post 428
follows around the cam section 422 of the cam gear 412. The spring 278 is
extended in these positions compared to the extension of spring 278 in
FIG. 23B.

[0148] FIG. 23E shows the cam plate 416 rotating back to a position in
which the semi-circular section 420 is adjacent to the post 428. When
this occurs, if there was no bone stock between the front face 306 and
the cutter 48 the arm 300 would move to the fully clockwise position
under the bias of spring 278, which would also rotate the cam follower
426 clockwise such that the post 428 contacted the outer surface 418 of
the cam plate 416 on the semi-circular section 420. However, FIG. 23E
depicts a typical cleaning situation in which bone stock is trapped
between the front face 306 and the cutter 48 and is being cleaned by the
cutter (see FIG. 11A). Thus, the arm 300 is impeded by the bone stock,
which opposes the force provided by spring 278. As a result, the arm 300
is unable to rotate completely into the fully clockwise position abutting
shaving tube 270. Instead, the arm 300 is in an engaged position in which
the trapped bone stock is being pressed into the cutter 48. The trapped
bone stock causes the arm 300 to be spaced from the shaving tube 270 and
cutter 48. Owing to the abutting first and third surfaces S1 and S3, cam
follower 426 is also not allowed to fully rotate clockwise such that the
post 428 is spaced from (or lifted off) the outer surface 418 of the cam
plate 416.

[0149] Cam follower 426 and hub 318 of arm 300 pivot about cam follower
axis A5, as shown in FIG. 23F. A bearing member B may be located between
the cam follower 426 and top 216 of shell 200 to allow rotation of the
cam follower 426 in the top 216. Similarly, a bearing member B is located
between hub 318 and cleaning module base 245 to allow rotation of hub 318
in the cleaning module base 245. When the cleaning module 46 is placed on
the drive module 45, the hub pivot pin H centers into a central bore (not
numbered) in the cam follower 426 to align the cam follower 426 to the
hub 318.

[0150] Referring back to FIG. 22, an indexing gear 432 is disposed for
rotation about indexing central axis A6 in shell 200. The indexing
central axis A6 is fixed relative to shell 200. The indexing gear 432
includes an indexer spur gear 434. An indexing plate 436 is fixed to an
upper surface of the indexer spur gear 434. The indexing plate 436
defines a plurality of indexing grooves 438. Four indexing grooves 438
are provided in the embodiment shown. The indexing grooves 438 are
equally circumferentially located every 90 degrees about the indexing
central axis A6. Indexing grooves 438 start at a position spaced from
indexing central axis A6, are elongated in a radial direction therefrom,
and terminate short of outer perimeter of indexer spur gear 434.

[0151] An indexer pin 440 depends downwardly from a bottom surface of cam
spur gear 414 (see FIG. 25). The indexer pin 440 is spaced radially
inwardly from a perimeter of the cam spur gear 414, yet radially
outwardly from the cam gear axis A4. When cam spur gear 414 is driven,
indexer pin 440 rotates about cam gear axis A4. The indexer pin 440 is
configured to engage the indexing plate 436 and slide into the indexing
grooves 438. For every one rotation of the cam spur gear 414, the indexer
pin 440 engages one indexing groove 438 and rotates the indexing gear 432
one-quarter of a turn or 90 degrees about indexing central axis A6. This
arrangement is conventionally referred to as a geneva drive in which the
cam spur gear 414 is a drive wheel and the indexing gear 432 is a driven
wheel. A blocking disc 439 of this geneva drive is shown in FIG. 25. The
blocking disc 439 locks the driven wheel in position between steps.

[0153] The bottom end 276 of shaving tube 270 is press-fit into the
ring-shaped spur gear 448 to rotate with rotation of the ring-shaped spur
gear 448. The ring-shaped spur gear 448 is thus part of the cleaning
module 46 in the embodiment shown. In other embodiments, the ring-shaped
spur gear 448 forms part of the drive module 45.

[0154] Ring-shaped spur gear 448 is rotatable relative to the drive gear
226 about central axis A. In another connection made when the cleaning
module 46 is mounted to the drive module 45, the ring-shaped spur gear
448 engages lower spur gear 444. The tube gear 442 is configured so that
one quarter turn of the indexer spur gear 434 results in one complete
rotation of 360 degrees of the ring-shaped spur gear 448 and shaving tube
270.

[0155] Pivot pins P having heads and threaded ends are used to secure the
coupler gear 401, speed reducing gear 406, cam gear 412, indexing gear
432, and tube gear 442 to the shell 200 of drive module 45. In the
embodiment shown top 216 of shell 200 includes internally threaded bosses
to which the pivot pins are attached (see, e.g., FIG. 6). A similar boss
is located on cleaning module top 249 to receive hub pivot pin H (pivot
pin with threaded end, but without head) for rotatably supporting the hub
318. Spacers S may be provided about pivot pins P to space certain gears
from top 216 as appropriate (see FIG. 6). The gears 401, 406, 412, 432,
442, cam follower 426, and hub 318 are configured to rotate about the
pins P, H, which define axes A2-A7. These axes A2-A7 are also fixed in
relation to each other and parallel to one another.

II. Operation

[0156] During operation, uncleaned bone is first placed in the void space
252/bone stock space 302 for cleaning and the lid 500 is then rotated
into place relative to cleaning module shell 250 via slide handle 504 to
cover the void space 252. The uncleaned bone includes soft tissue
attached thereto that requires removal without damaging the periosteum
layer.

[0157] The cleaning module 46 is then fitted to the drive module 45, after
the drive module 45 is releasably locked to the base unit 42. In some
embodiments, the uncleaned bone is placed in the void space 252/bone
stock space 302 after these steps.

[0158] The surgical personnel actuate the cleaning module 46 by depressing
the push button of base unit switch 98. In response to the depression of
switch 98 the motor controller (not illustrated) causes power to be
applied to the motor 44, which energizes the motor 44 and causes its
output shaft 78 to turn in a direction that drives rotation of cutter 48
counterclockwise as viewed from above.

[0159] The tumble plate 290 rotates in unison with the cutter 48 in the
counterclockwise direction. Tumble plate 290 operates to move the bone
stock so that the bone stock is ultimately positioned between the front
face 306 of press block 304 and cutter 48. In the engaged position, front
face 306 presses the bone stock toward shaving rotor 260 of cutter 48
through window 272 in shaving tube 270 to cut soft tissue from the bone
stock.

[0160] The cutting edges 264 of shaving rotor 260 and/or shaver edges 274
of shaving tube 270 cut away soft tissue from bone. The cut soft tissue
and other debris is then augered upwardly between the shaving rotor 260
and shaving tube 270. The augered tissue is stored for later retrieval or
disposal. This provides a separation of soft tissue and other debris from
the remaining bone of the bone stock.

[0161] After some amount of bone cleaning takes place, gear train 201 is
configured to rotate shaving tube 270 about central axis A to dislodge
bone stock trapped therein. The arm 300 provides a bearing surface
against which trapped bone stock can bear as it is loosened or dislodged
from cutter 48 and/or shaving tube 270 when the shaving tube 270
rotates--with the arm 300 in either engaged or disengaged positions, and
sometimes when the arm 300 is in an extreme counterclockwise position
(see FIG. 23D). The gear train 201 is configured so that the shaving tube
270 rotates about central axis A between 0 and 360 degrees once every 1
to 5 seconds with alternating periods without rotation in which arm 300
is actively pressing bone stock into cutter 48 through the window 272.

[0162] During cleaning, gear train 201 periodically pivots arm 300 between
the engaged and disengaged positions to reorient the bone stock trapped
between the arm 300 and the cutter 48/shaving tube 270. The arm 300
pivots between the engaged and disengaged positions about 5 to 20 times
per minute. This further facilitates removal of soft tissue and debris
from all surfaces of the bone stock.

[0163] Once the cleaning module 46 has sufficiently removed soft tissue
from the bone, the bone is removed from the cleaning module 46. In one
embodiment, the lid 500 is rotated by slide handle 504 to expose opening
506. Next, the cleaned bone is grabbed by forceps or other device (not
illustrated) to be placed in a collection tray for further processing. In
other embodiments, not shown, the bone is gathered automatically into the
collection tray (not illustrated), which is then removed from the drive
module 45 or the cleaning module 46--depending on which module is used to
hold the collection tray.

[0164] At the conclusion of the cleaning process, the cleaning module 46
is removed from the drive module 45. Drive module 45 is also released
from base unit 42. The cleaning module 46 may then be discarded (or
cleaned in some embodiments). The drive module 45 and base unit 42 are
then cleaned for reuse.

[0165] One advantage of the system 40 is that it provides a mechanized and
automated manner of cleaning the bone stock that substantially reduces
the need for surgical personnel to grasp and clean the bone manually.

[0166] Likewise it should be understood that while this invention is
intended for use to clean autograft bone, its applications are not so
limited. System 40 of this invention may also be used to clean donor
bone, sometimes referred to as allograft bone, or to clean or process
other materials.

III. Alternative Embodiments

[0167] In some embodiments, the components of the drive module 45 are
integrated into the base unit 42. In these embodiments, the cleaning
module 46 connects directly to the base unit 42. In yet other
embodiments, the components of the drive module 45 are integrated into
the cleaning module so that the gear train 201 forms part of the cleaning
module.

[0168] In some embodiments, rotation of the shaving tube 270 occurs in
alternating clockwise and counterclockwise directions. Oscillating
movement of the shaving tube 270 helps to dislodge and release bone stock
caught between the shaving rotor 260 and shaving tube 270. In yet other
embodiments, the shaving tube 270 may be rotated less than 360 degrees,
such as from 90 to 270 degrees. Further, constant or periodic oscillation
of shaving tube 270 about central axis A could be employed.
Alternatively, constant rotation of shaving tube 270 in the same
direction could be employed to dislodge trapped bone stock. The drive
module 45 can be configured for any of these scenarios, or any
combination thereof.

[0169] In some embodiments, when arm 300 is in the engaged position, but
after some amount of bone cleaning takes place, shaving tube 270 may be
rotated completely about central axis A to dislodge bone stock trapped
therein. In other embodiments, when the arm 300 is in the extreme
counterclockwise position (see FIG. 23D), a projection (not illustrated)
on inner surface 308 of arm 300, opposite the press block 304, provides a
bearing surface against which trapped bone stock can bear as it is
loosened or dislodged from cutter 48 and/or shaving tube 270 when the
shaving tube 270 rotates.

[0170] The materials from which the components of this invention are
fabricated and the geometry of the components may be different from what
has been described. For example, in embodiments of the invention having
components intended to be disposable, some or all of those components may
be made of sterilizable plastic instead of being made of metal. In
certain embodiments, the cutter 48, shaving tube 270, bearing members B,
and gears are formed of metal such as stainless steel, while the shells
200, 250, tumble plate 290, and arm 300 are formed of sterilizable
plastic. In some embodiments the gears are also formed of sterilizable
plastic. In some embodiments the cutter 48 and shaving tube 270 are also
formed of sterilizable plastic.

[0171] It is envisioned that in another alternative embodiment, the drive
module 45 includes a separate, reversible stepper or servo motor (not
illustrated) mounted to the shell 200 that directly drives the drive gear
226, and the required controls are mounted to the shell 200. Accordingly,
the drive module 45 does not require mounting to the base unit 42.

[0172] It is further envisioned that in alternative embodiments, the gear
train 201 includes a separate reversible stepper or servo motor (not
illustrated) mounted to shell 200 that directly drives the arm 300,
separately from the cutter 48, shaving tube 270, and tumble plate 290.
This motor includes an output shaft connected directly to the hub 318. In
this embodiment, the force limiting feature that limits damage to the
osteoblastic progenitor layer is integrated in the control unit to the
arm motor. More particularly, force is limited by sensing motor current
and adjusting motor voltage to maintain motor current below a
predetermined set point corresponding to a given torque. The selected
torque is determined based on the relationship between torque and damage
to the osteoblastic progenitor layer. The selected torque removes
unwanted material from the bone stock yet substantially maintains the
osteoblastic progenitor layer.

[0173] Power may be supplied to the base unit motor 44, in some
embodiments, by a battery powered control unit (not illustrated). The
battery powered control unit supplies electrical energization signals to
the base unit motor 44 to actuate the base unit motor 44. The battery
powered control unit is integrated into the base unit 42. Additionally,
power received from console 50 through cable 52 and socket 100 or from
the battery powered control unit is regulated by the motor controller and
provided to the windings of base unit motor 44 when switch 98 is
electrically closed. Power to the base unit motor 44 may be provided
continuously when the push button is actuated, and then discontinued when
the push button 98 is actuated a second time, or power may be provided
for a predetermined period of time such as 2 minutes after actuation of
the push button 98. Alternatively, the push button 98 may be a rocker
switch having on and off positions.

[0174] In some embodiments, flutes on the cutter have shapes other than
helical, such as vertical flutes. Additionally, the cutter may have less
flutes or more flutes. The flutes may have a larger or smaller helix
angle. The cutter may also have cutting edges with a larger or smaller
rake angle.

[0175] In some embodiments, the shaver edges may be blunt so as to provide
impingement to sever soft tissue caught between the shaving rotor 260 of
cutter 48 and the shaving tube when the shaving rotor 260 rotates
relative to the shaving tube.

IV. Alternative Cleaning Module

[0176] Referring to FIGS. 29-50, an alternative cleaning module 1046 is
shown. Alternative cleaning module 1046 includes a shell 1200. Shell 1200
is dimensioned to fit to the base unit 42 so that the base unit motor 44,
when actuated, drives cutter 1048. Shell 1200 defines a void space 1202
for receiving harvested and uncleaned bone stock. During use, cutter 1048
cleans the bone stock in the shell void space 1202 by cutting soft tissue
and other debris from the bone stock.

[0177] Shell 1200 has a base 1208. Shell base 1208 includes a lower wall
1210. Shell base lower wall 1210 has an outer periphery that allows the
shell 1200 to be slip fitted into the void space 164 above pedestal top
surface 60 and within lip 62. Shell base lower wall 1210 is coterminous
with lip 62 on both sides of notch 68 so that shell base lower wall 1210
is semi-cylindrical.

[0178] Four circumferentially and equiangularly spaced apart notches 1212
extend radially inward in, and axially upward from, a downwardly directed
face of the base lower wall 1210 (only one notch is shown in FIGS. 31 and
32). Notches 1212 are dimensioned so that when the shell 1200 is fitted
to base unit 42, pedestal teeth 70 are seated in the notches 1212.
Engagement of the teeth 70 and notches 1212 prevents unwanted rotation of
the shell base 1208 relative to the base unit 42 during operation.

[0179] Shell base lower wall 1210 is further provided with two additional
side notches 1214 (see FIG. 29) that are diametrically opposed from each
other. Side notches 1214 extend radially inwardly from an outer
cylindrical surface of the base lower wall 1210 at a location above the
bottom of the base lower wall 1210. More particularly, shell 1200 is
formed so that when the shell 1200 is seated in pedestal void space 64
and teeth 70 are seated in notches 1212, side notches 1214 are positioned
to receive the radially inwardly directed fingers 74 of retention arms
72. The fingers 74 are biased radially inwardly to seat against
cooperating surfaces of the side notches 1214 to selectively lock shell
1200 to base unit 42. The upper surfaces of fingers 74 may be downwardly
angled radially inwardly. This allows shell 1200 to slidably engage and
move fingers 74 radially outward against the biasing force acting on
retention arms 72. Thus, shell 1200 may be pushed downwardly past the
fingers 74 and received in void space 64 without levers 76 being manually
actuated.

[0180] Shell base 1208 further includes a base plate 1216 mounted to base
lower wall 1210. Shell base lower wall 1210 extends downwardly from base
plate 1216 to define a lower cavity 1218 of shell 1200. Shell lower
cavity 1218 has a diameter that is larger than the diameter of spindle
head 90. This allows the spindle head 90 to be received in the lower
cavity 1218.

[0181] A center opening 1220 is defined in and through the base plate
1216. A support tube 1222 is mounted to the base plate 1216 and has an
upper end that is received in center opening 1220. A lower end of support
tube 1222 projects into lower cavity 1218. The support tube 1222 includes
a flange 1224 located between the upper and lower ends of the support
tube 1222. Flange 1224 is fixed to the bottom surface of the base plate
1216 by welding, fasteners (not illustrated), ultrasonic welding,
adhesive, or the like.

[0182] A coupler shaft 1226 is supported to rotate within the support tube
1222. Bearings 1228 are positioned inside support tube 1222 to rotatably
support the coupler shaft 1226. The coupler shaft 1226 is tubular in
shape and has an axially upper section and an axially lower section,
which are separated by an axially intermediate section (sections not
numbered). Bearings 1228 are disposed about the upper and lower sections.
Upper and lower sections have a common diameter. The diameter of
intermediate section is relatively larger than that of upper and lower
sections. Owing to its larger diameter, intermediate section defines
opposing annular shoulders by which the bearings 1228 are axially spaced
and against which they respectively abut.

[0183] An annular groove (not separately numbered) is formed in an inner
cylindrical surface of the support tube 1222. Groove is located near but
axially spaced from the lower end of the support tube 1222. A retaining
ring 1242 is seated in the groove and projects radially inwardly from the
tube's cylindrical wall. The lowermost bearing 1228 axially abuts
retaining ring 1242 which limits the downward movement of that bearing
1228 and coupler shaft 1226 within support tube 1222. Thus, the bearings
1228 and the coupler shaft 1226 are supported within the support tube
1222. Retaining ring 1242 may, for example, be a circumferentially split
ring of known type.

[0184] During assembly of shell 1200, bearings 1228 and coupler shaft 1226
are first assembled and then positioned in the support tube 1222. Once in
place, the retaining ring 1242 is seated in the groove 1240 to axially
support the bearings 11228 and coupler shaft 1226 within support tube
1222. The coupler shaft 1226 is thus supported by the bearings 1228 for
rotation relative to the support tube 1222 during operation of bone
cleaning system 1040.

[0185] A receiver head 1244 is located at a lower end of the coupler shaft
1226 below retaining ring 1242. The receiver head 1244 is mounted and
rotatably fixed to the axially lower end of coupler shaft 1226. Receiver
head 1244 can be mounted to the coupler shaft 1226 by being threaded or
welded thereto, or by another suitable means facilitating their rotating
in unison. When shell 1200 is received in void space 64 of pedestal 58,
receiver head 1244 engages the spindle head 90. Driving torque is
transferred from the spindle head 90 to the coupler shaft 1226 through
the receiver head 1244.

[0186] Receiver head 1244 has a downwardly directed face with recesses
having corresponding shapes and locations that cooperate with those of
the alignment pin 92 and the drive teeth 94 protruding upwardly from the
top surface of the spindle head 90. More particularly, receiver head 1244
includes a centrally located alignment pin recess 1246 and four
circumferentially and equiangularly spaced apart drive tooth-receiving
recesses 1248. Recesses 1246, 1248 mate with alignment pin 92 and drive
teeth 94, respectively. The walls of each drive tooth recess 1248 are
parallel to the respectively interfacing surfaces of the drive tooth 94
slidably received therein. Spindle head 90 and receiver head 1244 thus
define a dog clutch for transferring torque from the spindle head 90 to
the receiver head 1244 when shell 1200 is received in void space 64 of
pedestal 58, and teeth 94 and recesses 1248 are mated. In the embodiment
shown, the spindle 90 can be raised as needed to mate with the receiver
head 1244.

[0188] Cutter 1048 is located within shell void space 1202. The cutter
1048 is supported by shell base 1208 to rotate about shell central axis
A10. The cutter 1048 has an axially lower stub shaft 1254 with a D-shaped
cross section that fits within a cooperating D-shaped axial bore (not
separately numbered) in the axially upper section of tubular coupler
shaft 1226. The lower stub shaft 1254 of cutter 1048 has one flat 1256
that forms its D-shaped cross section. Owing to the non-circular geometry
of the D-shaped cross sections of lower stub shaft 1254 and its receiving
bore in coupler shaft 1226, the cutter 1048 and coupler shaft 1226 are
angularly fixed about axis A10 for rotation together. The cutter 1048 and
coupler shaft 1226 rotate from 100 to 500 RPM.

[0189] Cutter 1048 also has an axially upper stub shaft 1258. A shaving
rotor 1260 of the cutter 1048 is located axially intermediate the lower
1254 and upper 1258 stub shafts. The shaving rotor 1260 is generally
cylindrical and has an outer diameter that is larger than the diameters
of the lower 1254 and upper 1258 stub shafts. The shaving rotor 1260,
upper stub shaft 1258, and lower stub shaft 1254 are integrally formed.

[0191] A shaving tube 1270 extends coaxially about the shaving rotor 1260
of cutter 1048. Shaving tube 1270 defines a pair of diametrically opposed
cutter windows 1272 through which tissue attached to the bone stock is
received for engagement by the cutter 1048. Each cutter window 1272 is
bounded by at least one shaver edge 1274. The shaver edges 1274 are sharp
so as to cut soft tissue caught between the shaving rotor 1260 of cutter
1048 and the shaving tube 1270 when the shaving rotor 1260 rotates
relative to the shaving tube 1270. The shaver edges 1274 also act as
impingement structures against which soft tissue abuts and is temporarily
held to facilitate cutting by shaving rotor 1260 of cutter 1048.

[0192] Bearing 1276 is located between upper stub shaft 1258 of cutter
1048 and shaving tube 1270. Another bearing 1278 is located between lower
stub shaft 1254 of cutter 1048 and the shaving tube 1270. Bearings 1276,
1278 allow for relative rotation between the shaving tube 1270 and the
cutter 1048.

[0193] In the embodiment shown, shaving tube 1270 is rotated about axis
A10 by a drive belt 1280. Shaving tube 1270 has a driven pulley 1282
integrated into shaving tube upper end. A belt drive shaft 1284 is
journaled in the base plate 1216 by a bearing 1286. A belt driving pulley
1288 is coaxially mounted on upper end of belt drive shaft 1284. The
drive belt 1280 is taughtly disposed around driven pulley 1282 and
driving pulley 1288. Shaving tube 1270 is rotated about axis A10 via the
drive belt 1280 when the belt drive shaft 1284 is actuated.

[0194] A drive assembly 1400 actuates the belt drive shaft 1284. The drive
assembly 1400 includes the receiver head 1244 and a gear train 1402.
Receiver head 1244 acts as a torque input for the gear train 1402 of the
drive assembly 1400. More particularly, the receiver head 1244 transfers
torque from the drive spindle 86 to the gear train 1402. In certain
embodiments, the receiver head 1244 has outer gear teeth (not
illustrated). The gear train 1402 operatively interconnects the gear
teeth of receiver head 1244 to belt drive shaft 1284 to transfer torque
from the receiver head 1244 to the belt drive shaft 1284.

[0195] The gear train 1402 is configured so that the shaving tube 1270
rotates about axis A10 between 0 and 360 degrees once every 1 to 5
seconds and in alternating clockwise and counterclockwise directions.
Oscillating movement of the shaving tube 1270 helps to dislodge and
release bone stock caught between the shaving rotor 1260 and shaving tube
1270. Constant or periodic oscillation of shaving tube 1270 about axis
A10 could be employed. Alternatively, constant or periodic rotation of
shaving tube 1270 in the same direction could be employed to dislodge
trapped bone stock. The gear train 1402 can be configured for any of
these scenarios, or any combination thereof. Mechanisms by which
continuous rotating input motion in a single direction is converted to an
oscillating angular output motion may be incorporated into the gear train
1402. Such mechanisms include quick return or bell crank mechanisms,
which are well known to those of ordinary skill in the art.

[0196] Shaving tube 1270 rotates, either in the same direction or opposite
directions at about 30 to 120 RPM. Owing to the helical geometry of
flutes 1262, and the relatively slow rotation of shaving tube 1270
compared to cutter 1048, as the cutter 1048 rotates cut soft tissue is
augered axially upwardly along cutter 1048 between the cutter 1048 and
the shaving tube 1270.

[0197] Two diametrically opposed debris windows 1290 are formed in shaving
tube 1270. Debris windows 1290 are located above and are axially spaced
from the cutter windows 1272. Debris windows 1290 are also
circumferentially arranged at a 90 degree offset about axis A10 from the
cutter windows 1272. Soft tissue that is cut from the bone stock during
processing and augered axially upwardly along shaving tube 1270 by
shaving rotor 1260 exits through the debris windows 1290.

[0198] A deflector ring 1292 is captured between bearing 1276 and shaving
rotor 1260 to deflect the cut and augered soft tissue out of the shaving
tube 1270 through the debris windows 1290. The deflector ring 1292 is
coaxial with cutter 1048 and has a frustoconical outer surface 1294 with
its diameter increasing from bottom to top. The outer surface 1294
provides a deflection surface against which the soft tissue being augered
upwardly is urged radially outwardly and through the debris windows 1290.

[0199] At the top of the deflector ring 1292 the diameter of the outer
surface 1294 is the same as or slightly smaller than the outer diameter
of bearing 1276. At the bottom of the deflector ring 1292 the diameter of
the outer surface 1294 is smaller than the major diameter of the shaving
rotor 1260 defined by the cutting edges 1264 at the radially outer edges
of the flutes 1262. This bottom diameter of deflector ring 1292 is the
same as the minor diameter of shaving rotor 1260 defined by the radially
innermost surfaces of cutter flutes 1262.

[0200] Debris catches 1296 receive from debris windows 1290 cut soft
tissue that has been augered upwardly along the shaving rotor 1260
between the cutter 1048 and the shaving tube 1270. The augered and
deflected soft tissue is collected on the debris catches 1296 for later
use or disposal.

[0201] A circular tumble plate 1298 is rotatably fixed to the coupler
shaft 1226. The bone stock sits on top of the tumble plate 1298 during
cleaning so that, when actuated, the tumble plate 1298 carries the bone
stock to and from the cutter 1048. Referring to FIG. 31, tumble plate
1298 has a central, D-shaped aperture 1300 that cooperates with D-shaped
cross section of lower stub shaft 1254 that extends therethrough. The
cooperation between the D-shaped stub shaft 1254 and central tumble plate
aperture 1300 rotatably fixes the tumble plate 1298 to the cutter 1048.
During assembly, the D-shaped cross section passes through the D-shaped
center aperture 1300 of tumble plate 1298 and into cooperating D-shaped
bore in coupler shaft 1226. Cutter 1048, tumble plate 1298, and coupler
shaft 1226 are thus rotatably fixed together for simultaneous rotation.
During operation of system 1040, tumble plate 1298 is thus driven about
the central axis A10 by coupler shaft 1226.

[0202] The upper surface 1301 of the tumble plate 1298 carries the bone
stock. In the embodiment shown, the upper surface 1301 is flat and
smooth. In some embodiments, the upper surface 1301 is textured or has
gripping features (not illustrated) to grip the bone stock and facilitate
moving the bone stock to the cutter 1048.

[0203] An arm 1302 extends over the planar upper surface of tumble plate
1298. When it is actuated, the arm 1302 moves across the tumble plate
1298 between disengaged and engaged positions. In an extreme clockwise
position, the arm 1302 is generally located along a periphery of the
circular tumble plate 1298.

[0204] FIG. 33 shows arm 1302 in a disengaged position. Arm front face
1304 is oriented so that, in a disengaged position, the front face 1304
cooperates with the inwardly directed arcuate surface 1252 of the
containment ring 1250 to further define the shell void space 1202. The
arm front face 1304 forms a nearly continuous surface with the inwardly
directed arcuate surface 1252 of containment ring 1250 when in the
disengaged position. When the arm 1302 is out of this disengaged position
and moving toward the cutter 1048 it diverts bone stock on the rotating
tumble plate 1298 toward the rotating cutter 1048.

[0205] FIGS. 34 and 35 show arm 1302 in an engaged position (bone stock
not shown). When the arm 1302 is in an engaged position, the front face
1304 guides bone stock toward the shaving rotor 1260 of cutter 1048
through the windows 1272 in shaving tube 1270. More particularly, bone
stock carried by the tumble plate 1298 is diverted by arm front face 1304
toward the cutting edges 1264 of cutter 1048. Arm front face 1304 acts as
a bearing surface that presses bone stock into windows 1272 and against
the cutting edges 1264.

[0206] Referring specifically to FIG. 35, the front face 1304 abuts
cylindrical outer surface 1377 of the shaving tube 1270 when the arm 1302
is in this engaged position. In versions where the shaving tube 1270
rotates, the cylindrical outer surface 1377 of the shaving tube 1270 is
in constant abutting contact with the front face 1304 to prevent the arm
1302 from intruding on the cutter 1048 and to maintain a gap or spacing
between the front face 1304 and the cutter 1048.

[0207] When arm front face 1304 engages or is at least in close proximity
to shaving tube 1270, but after some amount of bone cleaning takes place,
shaving tube 1270 may be rotated about axis A10 to dislodge bone stock
trapped therein. The arm 1302 provides a bearing surface against which
trapped bone stock can bear as it is loosened or dislodged from cutter
1048 and/or shaving tube 1270 when the shaving tube 1270 rotates.

[0210] Pivot shaft upper body 1310 and bore 1312 of arm 1302 have
complimentary non-circular shapes that cooperate to rotatably fix pivot
shaft 1306 and hub 1305. More particularly, they are each provided with
diametrically opposed flats, as shown in FIGS. 31 and 39. Pivot shaft
1306 and arm 1302 are thus angularly fixed for rotating in unison.

[0211] Pivot shaft 1306 is operatively connected to the gear train 1402.
Gear train 1402 transfers torque received from base unit motor 44 through
receiver head 1244 to pivot shaft 1306. Arm 1302 pivots upon actuation of
pivot shaft 1306 by gear train 1402. The gear train 1402 can include
mechanisms for transferring torque from the receiver head 1244 to the arm
1302 to reciprocate the arm between engaged and disengaged positions such
as a quick-return mechanism or sliding crank mechanism.

[0212] The gear train 1402 is configured to limit the force provided by
the front face 1304 of arm 1302 against the bone stock such that only
soft tissue is cut from the bone stock without damaging the periosteum
layer. The force can be limited by a force limiting clutch or other
feature/mechanism in the gear train 1402. The force limiting feature is
associated with the arm 1302 so that the force with which the arm 1302
presses bone stock into the cutter 1048 can be limited.

[0213] Arm 1302 is periodically reciprocated by the gear train 1402
between engaged and disengaged positions to reorient the bone stock
trapped between the arm 1302 and the shaving tube 1270. The arm 1302
pivots between the engaged and disengaged positions about 5 to 20 times
per minute. The speed at which the arm 1302 pivots between the engaged
and disengaged positions is from 5 to 20 RPM. Movement of the arm 1302
may be timed to the speed/motion of the shaving tube 1270 so that the arm
1302 is in the engaged position when the shaving tube 1270 is actuated.

[0214] Referring to FIGS. 37-39, the arm 1302 has generally planar top
1326 and bottom 1328 surfaces. The arm hub 1305 has a semi-cylindrical or
arcuate outer surface 1330 defined between the top 1326 and bottom 1328
surfaces. The arm 1302 further includes planar rear 1332 and side 1334
faces defined between the top 1326 and bottom 1328 surfaces. The rear
1332 and side 1334 faces intersect the arcuate outer surface 1330. The
rear face 1332 and side face 1334 are spaced from one another.

[0215] Rear face 1332 and side face 1334 lie in planes P1, P2,
respectively, that are substantially transverse to one another. The
planes P1, P2 lie at an acute angle a to one another. Spacing between the
rear face 1332 and side face 1334 increases as the faces 1332, 1334
extend further away from the hub 1305.

[0216] Arm front face 1304 is arcuate in shape and is defined between the
top 1326 and bottom 1328 surfaces. The front face 1304 faces the cutter
1048. A first edge 1336 of arm 1302 is formed at an intersection of the
front face 1304 and the side face 1334. The front face 1304 extends from
the first edge 1336 to a terminus edge 1338. The terminus edge 1338 is
formed at an intersection of end surface 1339 and front face 1304. The
arm 1302 in its engaged position adjacent the shaving tube 1270 defines
an inwardly directed path along which the bone stock on the rotating
tumble plate 1298 is guided towards the center of shell void space 1202
and the cutter 1048.

[0217] Referring to FIGS. 40-41, containment ring 1250 has a
semi-cylindrical or arcuate wall 1340 that extends more than 180 degrees
concentrically about axis A10. First 1342 and second 1344 wings are
integrally formed at each end of the wall 1340. First wing 1342 is shaped
to define a recess 1346 that receives a distal end of arm 1302 in a
disengaged position. Second wing 1344 is shaped to define a recess 1348
that receives a proximal end of arm 1302 in an engaged position.

[0218] Each wing 1342, 1344 has a threaded through bore 1350, 1352 for
threadedly receiving a set screw 1354, 1356. Set screws 1354, 1356 extend
through its threaded bore 1350, 1352 in containment ring 1250 and into
its recess 1346, 1348, respectively. The set screws 1354, 1356 are
adjustable in bores 1350, 1352 to adjust a gap between the arm 1302 and
the wings 1342, 1344, and tune the extreme positions of the arm 1302 by
adjusting the stop position of the arm 1302 in extreme clockwise and
counterclockwise positions. Set screws 1354 and 1356 abut arm rear face
1332 and side faces 1334 to adjust and tune the extreme arm clockwise and
counterclockwise positions, respectively, of the arm 1302. The terminal
ends of the set screws 1354, 1356 act as stops for the arm 1302 to
prevent its over rotation into recesses 1346, 1348 as it moves into its
disengaged and engaged positions, respectively. In the extreme
counterclockwise position arm 1302 is tuned so that front face 1304 is in
contact with or nearly in contact with shaving tube 1270. In the extreme
clockwise position arm 1302 is tuned so that front face 1304 is flush
with or nearly flush with inner cylindrical surface 1252 of containment
ring 1250.

[0219] Threaded bores 1360 are formed axially through the arcuate wall
1340 and wings 1342, 1344 and mate with clearance bores (not illustrated)
in base plate 1216 and lower wall 1210. Threaded fasteners (not
illustrated) are received from beneath into the clearance bores and the
threaded bores 1360 to attach the shell base lower wall 1210 and
containment ring 1250 to the base plate 1216.

[0220] As shown in FIGS. 42-44, fourteen flutes 1262 and corresponding
cutting edges 1264 are defined on shaving rotor 1260. Upper 1362 and
lower 1364 axial ends of shaving rotor 1260 are flat and lie in planes
perpendicular to axis A10. Flutes 1262 and cutting edges 1264 extend
between the ends 1362, 1364. The flutes 1262 and cutting edges 1264 are
arranged such that they helically wrap less than 180 degrees about
shaving rotor 1260 between ends 1362, 1364. The cutting edges each have a
rake angle of between 0 and 10 degrees and more preferably have a rake
angle of 7 degrees.

[0222] Referring to FIGS. 45-47, shaving tube 1270 is generally
cylindrical for fitting over cutter 1048. As shown in FIG. 45, the
shaving tube 1270 has diametrically opposed cut-outs 1372 formed in its
cylindrical wall (not separately numbered) that define the cutter windows
1272. Cut-outs 1373 are also formed in the shaving tube wall to define
the debris windows 1290.

[0223] Cut-outs 1372 create the sharp shaver edges 1274 that cut soft
tissue entering cutter windows 1272. A shaver edge 1274 is located on
both sides and the top of each cutter window 1272. Thus, the shaver edges
1274 further define the top and sides of the cutter windows 1272. Sills
1374 at the bottoms of the shaving tube windows 1272 formed by the
cut-outs 1372 are generally flat and parallel with the upper surface 1301
of the tumble plate 1298.

[0224] In the shown embodiment, the cut-out edges of each cutter window
1272 form a continuous shaver edge 1274. However, in alternative
embodiments, separate and distinct shaver edges may be provided along the
sides and top of each window 1272. The shaver edges 1274 are located so
that soft tissue trapped between shaving rotor 1260 and the inner
cylindrical wall of shaving tube 1270 is cut by the shaver edges 1274
either at the sides or at the top of the cutting windows 1272.

[0225] A base 1376 of the shaving tube 1270 is located below the cutter
windows 1272. In versions where the shaving tube 1270 rotates, the
cylindrical outer surface 1377 of the shaving tube 1270 is in constant
abutting contact with the front face 1304 of arm 1302 via the base 1376
to maintain a gap or spacing between the front face 1304 and the cutter
1048.

[0226] Referring to FIGS. 48-50, the debris catches 1296 include arcuate
mounts 1378 by which the debris catches 1296 are attached to the shaving
tube 1270. As best shown in FIG. 48, the arcuate mounts 1378 include tube
halves 1380. Tube halves 1380 mate with one another to form an outer tube
structure (not separately numbered) located coaxially about shaving tube
1270. Mounts 1378 have male projections 1382, 1383 that extend from the
tube halves 1380 and mating female notches 1384, 1385 recessed in the
tube halves 1380. The male and female mating projections 1382, 1383 and
notches 1384, 1385 engage one another to align the tube halves 1380 and
form the outer tube structure. The mating features 1382, 1383, 1384, 1385
and tube halves 1380 are secured to one another by adhesive, fasteners,
or the like.

[0227] Referring to FIG. 49, debris windows 1392 are formed in each tube
half 1380. The debris windows 1392 are aligned with the shaving tube
debris windows 1290. More particularly, alignment protrusions 1387 act to
align the windows 1290, 1392. Alignment protrusions 1387 extend inwardly
from a semi-cylindrical inner surface of tube halves 1380 on each side of
the debris windows 1392. Alignment protrusions 1387 are dimensioned and
shaped for receipt into the shaving tube debris windows 1290 adjacent the
opposite side edges of the cutouts 1373. The protrusions 1387 provide
axial alignment of the windows 1290, 1392 their opposite ends abutting
the opposite top and bottom edges of cutouts 1373. Protrusions 1387
provide radial alignment of the windows 1290, 1392 by their abutting
contact with the respective side edges of cutouts 1373.

[0228] Catch trays 1386 are attached to each arcuate mount 1378 below
debris windows 1392. Cut soft tissue that has been augered along the
interior of the shaving tube 1270, and deflected by deflector ring 1292
radially outwardly through debris windows 1290 passes through aligned
debris windows 1392 and is deposited onto the catch trays 1386 where the
soft tissue and other debris is ultimately collected. Each catch tray
1386 includes a bottom 1388 and a peripheral wall 1390 extending upwardly
from the bottom 1388. Peripheral wall 1390 holds and contains the soft
tissue and other debris deposited on the bottom 1388.

[0229] A lid 1500 is removably positionable on top of the containment ring
1250 of shell 1200 (see FIG. 30). The lid 1500 covers the shell void
space 1202 and the bone stock being cleaned. The lid 1500 has a slot 1502
for accepting the shaving tube 1270 when sliding the lid 1500 in place
over the shell void space 1202. A handle 1504 is fixed to the lid 1500.
Handle 1504 extends upwardly from the lid 1500 to be grasped by the user.
The user can slide the lid in place over the containment ring 1250 and
beneath the debris catches 1296 or remove the lid 1500 using the handle
1504.

[0230] During operation, uncleaned bone is first placed in the shell void
space 1202 for cleaning and the lid 1500 is then slid into place atop
containment ring 1250 to cover the void space 1202. Fasteners (not
illustrated) may be used to fasten the lid 1500 to the containment ring
1250 via threaded bores 1360. The uncleaned bone includes soft tissue
attached thereto that requires removal without damaging the periosteum
layer.

[0231] The alternative cleaning module 1046 is then fitted to the base
unit 42. The surgical personnel actuate the alternative cleaning module
1046 by depressing the push button of base unit switch 98. In response to
the depression of switch 98 the motor controller (not illustrated) causes
power to be applied to the motor 44, which energizes the motor 44 and
causes its output shaft 78 to turn in a direction that drives rotation of
cutter 1048 counterclockwise as viewed from above.

[0232] The tumble plate 1298 rotates in unison with the cutter 1048 in the
counterclockwise direction. Tumble plate 1298 operates to carry the bone
stock toward the front face 1304 of arm 1302 when the arm is out of its
disengaged position. In the engaged position, arm front face 1304 guides
the bone stock toward shaving tube 1270 and the cutter shaving rotor 1260
to cut soft tissue from the bone stock.

[0233] Cutting edges 1264 of shaving rotor 1260 and/or shaver edges 1274
of shaving tube 1270 cut away soft tissue from bone. The cut soft tissue
and other debris is then augered upwardly between the shaving rotor 1260
and shaving tube 1270. The augered tissue is deflected radially outwardly
by deflector ring 1292 into and through the debris windows 1290 in
shaving tube 1270 and windows 1392 in each tube half 1380. The tissue is
then collected onto catch trays 1386 for disposal. This provides a
separation of soft tissue and other debris from the remaining bone of the
bone stock.

[0234] After some amount of bone cleaning takes place, drive assembly 1400
rotates shaving tube 1270 about axis A10 to dislodge bone stock trapped
therein. The arm 1302 provides a bearing surface against which trapped
bone stock can bear as it is loosened or dislodged from cutter 1048
and/or shaving tube 1270 when the shaving tube 1270 rotates. The gear
train 1402 is configured so that the shaving tube 1270 rotates about axis
A10 between 0 and 360 degrees once every 1 to 5 seconds and in
alternating clockwise and counterclockwise directions.

[0235] During cleaning, drive assembly 1400 periodically pivots arm 1302
between engaged and disengaged positions to reorient the bone stock
trapped between the arm 1302 and the shaving tube 1270. The arm 1302
pivots between the engaged and disengaged positions about 5 to 20 times
per minute. This further facilitates removal of soft tissue and debris
from all surfaces of the bone stock.

[0236] Once the alternative cleaning module 1046 has sufficiently removed
soft tissue from the bone, the lid 1500 is removed. The catch trays 1386,
and soft tissue/debris collected in the catch trays 1386 are removed and
discarded. Next, the cleaned bone is grabbed by forceps or other device
(not illustrated) for further processing. At the conclusion of the
cleaning process, the alternative cleaning module 1046 is removed from
the base unit 42. The alternative cleaning module 1046 may then be
cleaned or discarded.

[0237] Obviously many modifications and variations of the present
invention are possible in light of the above description. While this
description is directed to particular embodiments, it is understood that
those skilled in the art may conceive of modifications and/or variations
to the specific embodiments shown and described herein. Any such
modifications or variations, which fall within the purview of this
description, are intended to be included herein as well. It is understood
that the description herein is intended to be illustrative only and is
not intended to be limited.